Alrighty so I recently bought a 2002 chevy camaro v6 manual(she needs a lot of work) okay but the main problem is it shakes but not at idle and shakes really bad in third but not fourth or fifth and sincd I had some time today I took out my tranny mount and nope its solid no wiggle can anyone help me or even give me a clue at what to look at

So I recently bought a 2002 chevy camaro v6 manual but when I bought it would shake not a whole bunch but noticeable but what threw me off is in third it makes the tranny hop and hit the tunnel but in fourth and fith shakes but not as bad so I thought tranny mount I checked and nope solid can anyone help me diagnose this